Top Trump adviser defends Aust dealings

US president-elect Donald Trump's recently-appointed national security adviser was investigated for inappropriately sharing highly-classified intelligence with Australian forces.

Retired US three-star lieutenant general Michael Flynn, a maverick who spent more than 33 years in US Army intelligence, worked alongside Australian forces in Afghanistan and Iraq.

An outspoken believer in assisting allies on the battleground despite red tape preventing the flow of information, Lt Gen Flynn said the sharing of intelligence with Australian and British forces that left him in hot water was done "with the right permissions".

Michael Flynn believes the US should be forthcoming with its military intelligence when it comes to dealing with allies. (Source: AFP) ()

His unconventional style and strong resume - he was tapped by US commander in Afghanistan General Stanley McChrystal to be his top intelligence officer and promoted by President Barack Obama as Defence Intelligence Agency director - was obviously attractive to fellow maverick Mr Trump.

Lt Gen Flynn was pushed out of the DIA job after two years in the role and has labelled Mr Obama a "liar".

He also raised eyebrows when he sat alongside Russian President Vladimir Putin at a lavish party in Moscow last year.

Offering insight into his more open, untraditional philosophy of sharing information, in 2010 he co-wrote the report Fixing Intel: A Blueprint for Making Intelligence Relevant in Afghanistan.

It concluded the US intelligence community "must open their doors to anyone who is willing to exchange information, including Afghans and NGOs (non-governmental organisations) as well as the US military and its allies".